1. Field of the Present Disclosure
The invention described herein relates generally to dental tools and more particularly to a hand tool and its method of use for facilitating a class II dental restoration.
Dental restorations that involve the damaged or lost outer surfaces of a tooth where that surface faces an interproximal space are known as class II restorations. Such restorations present unique problems as the outer surface of the damaged tooth must be returned to its former shape and the mutual contact between the restored tooth and its interproximal neighbor must be returned to its former condition. The standard technique to restore class II tooth surfaces is to surround the missing tooth structure with a temporary form or matrix strip. A matrix strip is usually a thin flexible metal or plastic strip which is inserted between teeth and wrapped around the damaged tooth, the strip being held in place by an adjustable metal retaining clamp. Restorative material, usually composite or amalgam, is then flowed or packed into the space confined by the matrix strip and the remaining tooth structure and then hardened. The shape of the matrix containing the restorative material thus directly defines the resulting exterior contour of the finished restoration. This contour is extremely important to the physiologic health of the tooth and its surrounding hard and soft tissues. If proper contact or contour with the adjacent tooth is not established, food impactions can occur causing periodontal disease or decay. If there is an excess of composite material present around the restoration due to a poorly adapted or positioned matrix, excessive finishing time is required to properly shape the restoration. It is therefore desirable to have a matrix system that replicates the original contour of the tooth as closely as possible, or even improve on it. Such a system must permit restoration in as little time as possible in order to make the procedure cost effective and practical. Also the procedure should be easy for the dentist to learn and to use.
The well known and most commonly used matrix system (Tofflemeyer) comprises three parts: a matrix strip, a matrix strip retainer, and a wedge. The free ends of the matrix strip are connected to the matrix strip retainer, which is placed around the tooth being restored. The matrix strip retainer is then tightened which takes up any slack in the strip and tightens it against the tooth. The shape of the tooth, however, may be quite irregular when the relatively flat matrix strip is tightened against a curved tooth contour that has a missing gap. Also, the thickness of the strip creates an undesirable interproximal space.
Clearly an extremely thin matrix strip that assumes the approximate shape of the original contour of the tooth is desirable. However, it is difficult to insert an extremely thin strip between teeth without tearing or distorting the strip. Wedges are used such as a tapered piece of wood or plastic having a triangular cross section. These are inserted between the teeth and abutting the matrix strip so as to wedge the matrix strip against the lower margins of the restoration between the teeth. This results in an improved anatomical shape in the restoration.
There have been improvements on the standard matrix strip and retainer system such as the Palodent System developed by Dr. Alvin Meyer. This system utilizes an open metal ring with bent ends called a “BiTine Ring,” and forms the matrix retainer, serving also as a tooth separator. This system uses a concave shaped sectional matrix along with a conventionally shaped wedge. The technique squeezes the embrasure space, that is, the contour of the surfaces between two teeth, and creates a separating force between the two teeth adjacent to the restoration. The sectional matrix is used with its spherical shape. Its ends are not attached to a matrix retainer, rather the BiTine Rings have bent ends which pinch the matrix against the tooth wall and separate the tooth at the same time. This system creates a better shaped restoration than the flat matrix strip of the Tofflemeyer system, however it has some shortcomings. First, the sectional matrix is spherical or convex, however the lower margin of the restoration (gingival margin) has a flat or even concave topography. Second, since the sectional matrix has no free ends for attachment to a retainer, the matrix cannot be pulled tightly or held tightly against the tooth. The only tightly held areas of the matrix are the small areas of the split ring's contact. This looseness of the matrix results in excess composite at the margins of the restoration causing additional finishing work. Third, the sectional matrix is also made from stamped metal which tens to crinkle and dent as it is being inserted and placed between teeth. Fourth, the split rings can slip off the tooth at an inappropriate time causing delay, extra work and possible damage to the restoration. Fifth, this system utilizes metal matrices which, not being transparent, tends to prevent illumination of a curing light from penetrating into the restoration.
Improved matrix strips are pre-contoured providing better shaped restorations. However, in use, the contoured portion of these strips is difficult to maintain when tightening the strip around the tooth. Also, they are usually a compromising shape that is ill-fitted for other than average sized teeth. Also, in those areas where the strip does not adapt to the tooth, excess composite collects resulting in, as previously stated, more work and time in finishing the restoration.
A matrix system that is adaptable to most tooth contours and all sizes of teeth, which is easy to use, and provides an improved patient experience in not known at this time.
2. Description of Related Art Including Information Disclosed under 37 CFR 1.97 and 1.98
Miller, U.S. Pat. No. 351,065, discloses a dental matrix consisting of two arms or portions fitted for insertion between the tooth to be filled and the adjacent tooth.
Thompson, U.S. Pat. No. 782,503, discloses a dental aid for preventing the packing of fillings into the interproximal spaces between teeth comprising an elongated, deformable, wedge-shaped strip tapering to a point at one end and being triangular in cross-section for insertion between the teeth for pressing a matrix band into conformance with the wall of a tooth at the gingival area of the tooth, the strip being mounted on a strip of dental floss.
Soelberg et al., U.S. Pat. No. 4,259,070, discloses a dental wedge system that has two interfitting circular-bodied wedges adapted to extend between adjacent teeth and to abut and hold a matrix disposed around one of the teeth.
Dragan, U.S. Pat. No. 4,704,087, discloses a retainerless dental matrix band which is preformed or contoured and which can be readily retained in place without a retaining tool. The matrix band comprises a curvilinear base portion having a connected upwardly and outwardly curved portion adapted to complement the shape of a tool and arranged to be disposed within the interproximal space between adjacent teeth, and fixedly retained in place by wedges and/or by bonded cotton pellets. The matrix is constructed for use with self cured or light cured composite resin dental material, and may be made of a light permeable material when used with light-cured composite materials.
Mogelof, U.S. Pat. No. 4,715,816, discloses a dental wedging system that includes an adjustable wedge characterized by a central bore positioned along a longitudinal axis of the wedge. A pair of opposed leaves separate along an apex of the wedge. A piston is used to variably separate the leaves. The adjustable dental wedging system can be used in conjunction with composite dental fibers for ensuring adequate inter-tooth separation.
Asher, U.S. Pat. No. 5,573,400, discloses an expanding dental wedge structure to be used in association with dental matrix bands as used for placing dental restorative materials. The pre-expansion shape in cross section is roughly triangular with the dimensions of the triangle decreasing along the length ending in a pointed manner. The wedge is to be inserted into the area between teeth, one of which is carrying a matrix band. After insertion, the wedge is exposed to moisture causing pronounced expansion, which through equal pressure on the tooth surfaces and gingival tissues involved does: press the matrix tightly against the tooth sealing out moisture contamination, absorb moisture, drying the surgical field, and decreases blood flow and subsequent bacterial and vital transmission.
Hughes, U.S. Pat. No. 6,435,874, discloses structures and methods which may be used for applying force to the base of a matrix band or cavity filling material mold during a cavity filling procedure. In a preferred exemplary embodiment of the present invention, a unitary body of elastic material is stretched preferably by applying force in opposite directions to the opposite ends of the unitary body such that a central portion of the body of material is thinned. The thinned portion of the unitary body may then be easily inserted in the space between two adjacent teeth next to the base of a matrix band or cavity filling material mold. After the unitary body has been inserted into the space between two adjacent teeth next to the base of the matrix band or cavity filling material mold, the force which has been applied to the opposite ends of the unitary body is then removed. As a result, the previously stretched elastic unitary body contracts and becomes thicker in its central portion that had been previously thinned. The contraction and thickening of the unitary body in the space between adjacent teeth fills this space and applies and outward force to the walls of this cavity. Accordingly, the contracted unitary body applies a force on the base of the matrix band or cavity filling material mold which forces the base of the matrix band or filling material mold adjacent to the base of the tooth to be filled.
Thoreson, U.S. Pat. No. 6,439,886, discloses a device having pliable walls for placement in the mouth of a patent to serve, in one manner, as a matrix barrier with walls of the device bearing upon opposed tooth surfaces. An inlet permits inflation of the device, as by a dental syringe, of the installed device. A valve closes under air pressure to seal the inlet which may also be closed by a fused inlet segment.
The related art described above discloses a very wide range of matrix systems. This indicates that there is a strong interest and need for improvements in this technology. The present disclosure distinguishes over the prior art providing heretofore unknown and significant advantages as described in the following summary.